Method of making open cores



R. A. NUGEN T.

METHOD OF MAKING OPEN CORES.

APPLICATION FILED MAY 6, I919.

" 1,310,768, 'PatentedJuly22', 1919.

' 1 STATES A norm-r A. museum, or soiurmvmm, mAssAoHUsn-rrs.

METHOD OF MAKING OPEN CORES.

State of Massachusetts, have invented new and useful Improvements injMethods of- Making Open Cores, ofwhich the following is a specification.

In the manufacture of many metal castin s e. .ufor lobeor ate valves it is n a g g g 9 necessary to employ open cores, so that the casting when finished will have an internal reparation web or other-component. The ofsuch open cores. has hereto ore been a tedious and expensive operation, requiring delicate manipulation and a high degree of skill on the part of the core maker. I have devised. a process for the manufacture ,of

such cores, which requires no greater skill or accuracy of workmanship than the manufacture of solid cores.

()n the accompanying drawing,-

Figure 1 illustrates the finished core.

Fig. 2 represents the core before it is baked with the fusible section in place.

Fig. 3 shows one of the molds for casting a the fusible sections' b Fig. 4 represents one member of the core Fig. 5 represents one of the fusible sections.

Fig. 6 illustrates a section of a finished globe valve body produced (except for the.

ghreading) by the use of the core shown in i is has been stated, it has heretofore been. a delicate and tedious operation to produce an open core such as shown for example in Fig. 1. In this figure, the core is provided with the two opposite cylindrical end members a a and the lateral cylindrical member b.- These extend from a convex body which isroughly elliptical in longitudinal section and circular in cross section, but which in fact consists of the two similar portions 0' 0.

, connected by the integral central pillar' d.

Such a core is utilized in casting a valve body 10 as shown in- Fig. 6, in which the web 11 divides the-body into two chambers 12, 13, with the port 14 opening. from one into the other. The space between the portions 0 c of the core permits the metal to flow between them for the formation of the web V 11, whereas the presence of the'connecting pillar insures the formation of the port or opening 14. The web, as shown, has a longishown in Fig.

tudinal portion in the axis of the body extending from one side wall to the other with one end upturned as at 112 and the other end downturned as at 113 and merging in the wall of the body so that oneend opening 15 communicates with the chamber 13 and the other end opening 16 commumconstruction, and the finished core does'not 4 differ from those employed in producing it,

so that it will be understood that they are selected only as illustrations in making clear what is meant by an open core and in describing the results which may be secured by the process which I shall now describe in producing an open core.

cates with theopening 12. 1 This is standard My process consists broadly in building or forming the core with a section of fusible material which is incorporated in the core when it is initially formed and molded, but which, when the core is baked, melts and flows from the core leaving the latter with a free s ace or opening, such for example as may e necessary in casting an internal web 11 as described; 7

Assuming that it is desired to produce a finished core as in Fig. 1, I proceed as follows: By means of suitable molds (to be described) I produce a fusible section or member e, as shown in Fig. 5, which has the shape and dimensions of thefweb 11, 112, 113, except that at what may be called its ends it had the lugs f f. Such member has at its center an aperture 9 which is formed by the core material (6. e. sand or the like with the usual adhesive) to insure the formation of the'post or pillard.

In formin the core, I employ a core box consisting 0 two sections 17, one of whlch is shown in Fig. 4, and which are doweled together as. usual. Said sections are jointly formed with an internal cavity or chamber 18 of the shape of the finished core, except that at 19, 19, it is provided with notches or recesses to receive the lugs of the fusible 'member a. The sections of t e core box are first separated and the member is placed as t with the lugs located in the recesses 19 said lugs and recesses bemg angular an complemental to hold the member against dislocation. On closing the core box, the operative fills the box completel with the mixture of core-making materia so that it will be packed and compressed solidly therein and fill the opening 9 of the member e. Then the core box is opened and this temperature being sufiiciently high to melt the fusible members 6, the molten material flowing from the core and being caught bythe pan or tray. When the cores have been thoroughly baked, they present the appearance of that shown in Fig. 1. The molten material caught by the trays may be re-used in forming the sections 6. As shown, the exposed surfaces of the section (except the ears or lugs f) are flushwith the surfaces of the core before it "is backed, but this'depends upon the conformation of the ultimate casting.

In Fig. 3, I have indicated a sectional mold for casting the fusible members e. It consists of two mold box sections, of which one is shown at 20, having the recesses 21 and the mouth 22 to receive the molten material. 23 and 24 are removable elements (corresponding to the portions 0 0 ofthe core) and pin 25 which corresponds to the pillar d. These parts may be formed of brass or other suitable material. After the molten material has been poured inthe mold and has cooled and set, the'moldis opened,

the elements 23, 24 and 25, with the casting between them are removed, the pin 25- withdrawn, and the elements 23 and 24 separated leaving thecasting or member as shown in a wax or other composition which will be initially hard and unyielding and yet melt at a temperature at which the cores are baked.

What I claim is 1. A process of making open cores which consists in forming a fuslble member in the shape of the opening in the completed core, then forming the core of the usual material about said member, so that said member is embedded in such initially formed core, then baking said core and fusing said member so that it will flow from the core, leaving the latter in its finished 0 en condition.

2. A process of ma ing open cores which consists in forming a fusible member in the shape of the open ng inthercompleted core l and with'an aperture therethrough, placing such member in a core box. and packing the permitting the thus initially formed core with said member therein to set, then baking ROBERT A-NUGENT.

I have aflixed my .usual core-making material around such member and within the aperture therem, 

